A standard "manifold" wrench does the trick on those two lower manifold studs.

RedRon, perhaps one reason you didn't get much of a response is that overheating queries are so common that there really isn't any new ground to explore, so the same responses have been given over and over and over again. Perhaps some just get tired of repeating the same old info for those who don't search first.

That said, let me just reiterate some of the overheating culprits again. Retarded timing, blown headgasket, cracket head or block, excessive water pump impeller clearance or broken impeller, faulty thermostat, collapsed or soft radiator hoses, clogged water distribution tube, inadequate radiator flow rate (clogged), excessive scale build-up on water jackets, excessive bent or broken fins on radiator, or obstructed air flow, collapsed muffler internals and/or undersize tail pipe or exhaust pipe. In perhaps 75% of times it will be either a leaking headgasket or bad radiator.

Have you run the engine hot with the thermostat open and checked for gas bubbles in the top radiator tank (blown gasket or cracked head or block). Or you can use a sniffer and check for carbon monoxide. Have you checked the flow rate of the radiator - should be in the vicinity of 25-28 gallons per minute gravity flow.

I just want to add a little emphasis to Clipper47's comments about the distribution tube. It's purpose is to direct cool water flow, and most importantly to the hotest part of the engine, the exhaust valve seats. If it becomes filled with sludge and crap, a possible result is a cracked block, often between the exhaust valve seat and the cylinder. By all means despite the pain, remove it and clean or replace it.

Randy, my 56 Caribbean rear shocks are Gabriel 82066, and fronts are Gabriel 45653, gas filled as I remember. But if you just make note of the upper and lower mounting style, and the minimum compressed and maximum extended length, any auto parts guy "worth his salt" will give you all the alternatives.

Randy, my 56 Caribbean, a "late" (post #250) car, has the brace on both sides and I do believe the parts book calls for 2 per car so I think that clears that up. As to the really good question of whether its use was related to the heavier hoods used on Caribbeans, it would be enlightening to see if the 51-54 standard convertibles, and the 53-54 Caribbeans, had the same bracing. I think we'd all enjoy some feedback on this.

As to the fiberglass hood that was observed, the only postwar Packard I'm aware of that used a fiberglass hood was the '54 Panther Daytona and with only 4 made, I doubt there were many spares produced.

I'm quite certain the 53/54 Caribbean hoods were modified standard steel hoods, with the air scoop section added and leaded; thus the need for the hood support rods. 1955 hoods may indeed also contain considerable lead as they too have the support rods which 1956 Caribbean hoods don't; 56 hoods are VERY much lighter than 55s. Someone who has stripped a 55 hood in the course of repainting could confirm this.

Adding a frame-to-engine ground somewhere unobtrusive might be a good idea but really isn't generally needed because of two reasons: (1) there are MANY points of metal-to-metal attachment of car bodies to frames (for example, all the body mounting bolts), and (2) very few cars (our TL equipped V8 Packards the exception) have any electrical components that are frame-mounted. One the other hand the engine-to-body ground strap is important because once batteries moved out from under the front seat, they were generally grounded to the engine block and the driveline, being mounted in rubber mounts and further isolated by lubricants and moving connections, can easily lack a good ground. Another place to consider adding a ground is the gas tank; in restoration often the frame is heavily painted as is the tank, which itself is often isolated with webbing in the straps or retainers. If the fuel line (which is the tank ground) is interrupted for an in-line electric pump installed with rubber tubing connections, then this ground is lost. In such cases I usually install a ground from one of the fuel sender capscrews to a convenient frame rail.

Another "for what its worth" comment. Last weekend I both helped paint (with Kanter's Packard gray) a 1950 engine, and my own from porch deck and steps (with Benjamin Moore alkyd Deck Gray). The engine gray might have been a hint lighter, but not much. It appears very close to the "Crane Gray" that Packard used for their factory-reconditioned engine short blocks. I've not seen an original 48-54 engine with what I'd call "dark" gray.

Stokes Marine (and no doubt others) bought surplus Packard V8 engines (J.C. Whitney had them available new in crates for years) and marinized them themselves, thus they were unlike the IM-356 and IM-245 Packard marine engines which were built for marine use by Packard. A Stokes version Packard V8 marine engine is on display, at the Packard Proving Grounds I believe, along with several true Packard marine engines based on the 245 and 356 engines. In addition to being available with a variety of gear reductions via hydraulic gear boxes, the Packard IM-245 and IM-356 engines were also available in counter-rotating pairs which makes for some interesting internal changes, and also available in several different voltages. They also used updraft carburetion. Bob Neil's two books have a very considerable amount of information on the various Packard-built marine and aircraft engines.

When I read your original post about Hirsch not covering charges to correct his order, I did get in touch with him about it, so I'm glad your back in contact. I've known Bill for more than 30 years, he's a classy guy and would never expect a customer to pay for his own mistake.